Nanoporous Architecture of Mo Incorporated Nifeldh Oxygen Evolution Reaction (OER) Electrode for Efficient Water Electrolysis

Abstract

Designing efficient catalysts with non-precious metals is of utmost significance for a sluggish anodic reaction (oxygen evolution reaction) in large-scale hydrogen production via electrochemical water splitting. Towards this endeavor, this work presents a simple and scalable methodology for binder free direct growth of Mo-doped NiFe-layered double hydroxides (NiFeLDH) on a nickel substrate by electrodeposition route at room temperature. A three-dimensional (3D) porous nanosheet architecture of electrocatalyst delivers immense electrochemical surface area as well as abundant catalytically active sites. In addition, Mo doping in the NiFeLDH plays a vital role in regulating the OER catalytic performance. Furthermore, the fabricated electrocatalyst exhibits low overpotential (230 mV) at 30 mAcm−2 for oxygen evolution reaction (OER) in an alkaline electrolyte with ultralow Tafel slope of ~28 mV dec−1 and retains exceptional stability for 100 h. Furthermore, the optimized Mo doped NiFeLDH electrode was used as an anode in single cell lab-scale system for alkaline water electrolysis at 80 °C with continuous flow of alkaline electrolyte. The single cell exhibits efficient electrochemical performance with a lower cell voltage of 1.80 V at a current density of 400 mA cm−2. Also, an admirable long-term cell durability is shown by the cell for 24 h. This work encourages new designs and further development of electrode materials for alkaline water electrolysis to the commercial scale.